HEAT TRANSFER AND GLOBAL WINDS

HEAT TRANSFER AND GLOBAL WINDS SC State Standards 6-4.7 6-4.8 6-4.9

It’s TEAM Tuesday!!!January 25, 2011 Complete planner Turn in your SIGNED progress report and completed terrarium diagram On a separate piece of paper….. Entitle “The Water Cycle” + header Then write at least 3 things that you learned from yesterday’s class.

Solar energy • Solar energy is the main energy source that provides heat for Earth. • Heat circulates through the atmosphere through conduction, convection and radiation.

Solar Energy • Some of the sun’s energy is either reflected or absorbed by gases and/or clouds in the atmosphere. • Because of this, all of the energy from the sun does NOT reach the surface of the earth.

Greenhouse effect • Solar energy is absorbed by Earth’s land and water and is changed to heat. • This heat moves (radiates) back into the atmosphere, in the troposphere. • In the troposphere, gases absorb and trap the heat. THIS IS THE PROCESS KNOWN AS THE GREENHOUSE EFFECT!

Greenhouse Effect • Why do you think this process is called the Greenhouse effect? ____________________________ _____________________________

Solar energy and it’s effects on water and land: • LAND heats up quickly and releases it’s heat faster than water. • WATER heats up slowly and releases energy slower than the land does. **IT IS THE WATER ON EARTH THAT HELPS TO DETERMINE THE TEMPERATURE RANGE OF EARTH’S ATMOSPHERE**

Convection currents in the atmosphere are created because warm air near Earth’s surface rises and cool air moves in to take its place. How does this picture relate to the information given on the last slide?

Local Winds • Convection currents near bodies of water can cause local winds known as land and sea breezes • Land breeze movement of air from land to water because during the night the water is hotter than the land. • Sea breeze movement of air from water to land because during the day the land is hotter than the water.

Atmospheric convection currents: There are 3 atmospheric convection areas in the Northern hemisphere and 3 in the Southern hemisphere for a total of 6 convection areas. (we will focus on the Northern hemisphere) Northern Hemisphere convection areas: 1. tropical convection region 2. temperate region 3. polar region * The convection areas in the southern hemisphere are a mirror reflection of those in the northern hemisphere.

Tropical convection region begins at the equator (0°) and extends to about 30 degrees north latitude. • Temperate convection region extends from 30 degrees north latitude to about 60 degrees north latitude. • Polar convection region extends from about 60 degrees north latitude to the north pole (or 90 degrees north latitude)

CONVECTION ON A GLOBAL SCALE: • Causes global winds • Moves weather systems in particular directions • Affects ocean currents

Convection on a global scale (cont.)

How can these convection currents in the ocean affect the weather?

Ocean currents circulate warm and cold ocean waters and influence the weather and climates of landmasses nearby. • Water can "absorb" heat and transport it over great distances before releasing it. • The Gulf Stream is able to carry heat from locations near the equator all the way to northern latitudes that are usually associated with cold climates.

http://www.classzone.com/books/earth_science/terc/content/investigations/es2403/es2403page04.cfmhttp://www.classzone.com/books/earth_science/terc/content/investigations/es2403/es2403page04.cfm • The Californian Current, a cool ocean current in the North Pacific Ocean, flows from the Alaska, south along the U.S west coast. • Since the Californian Current brings cool water temperatures this will create cooler air temperatures along California as well. This means that the air coming from Alaska to California is also cool. However, the air is also quite moist as it travels over the Pacific Ocean. This is one reason why the West Coast often receives wet weather. • http://www.mvla.k12.ca.us/teachers/TeriF/Earth%20Science/Pages/FactorsthatAffectClimateTutorial.aspx

Cause: convection cells in the atmosphere and Earth spinning on its axis(Coriolis Effect)Effect: Global Winds* global winds are found in each convection region* trade winds, prevailing westerly winds and polar winds

JET STREAM: What is a jet stream? - a fast moving ribbon of air that moves around the Earth - it dips, bends and constantly changes positions. How does the jet stream affect the weather? - with the changes in the jet stream, air masses and weather systems in its path are moved along by the fast moving air.

EXAMPLES OF JET STREAM AND EFFECTS: * polar jet stream brings cold air down from cold polar conditions from north to south. *The polar jet stream was the cause of all of our winter weather!! *One of the most important impacts of the jet stream is the weather it brings… *The jet stream is a strong current of rapidly moving air, with the ability to push weather patterns around the world. * As a result, most weather systems do not just sit over an area, but they are instead moved forward with the jet stream. The position and strength of the jet stream then helps meteorologists forecast future weather events.

* subtropical jet stream brings warm tropical conditions from the south (in Northern hemisphere).

HEAT TRANSFER AND GLOBAL WINDS